Bar clamps are used extensively within the wood-working and construction industries to create an inward clamping force, resulting in an inward pressure between opposing jaws of the clamp, to temporarily hold two articles together for bonding to one another via gluing, screwing, nailing, welding or other methods known in the art. Various types of bar clamps are presently known within the industry. One common type of bar clamp is the one-handed or “quick-grip” clamp. Such quick-clamps typically include a trigger or toggle mechanism that is hand actuated to move the opposing jaws, usually connected by a “bar,” toward one another to create the inward pressure requisite of holding the articles together. Such clamps also include a hand actuated release mechanism to release the inward pressure of the opposing jaws and to allow the jaws to be moved away from one another.
Presently-available quick-grip clamps, however, suffer numerous disadvantages. One such disadvantage is a failure of these clamps to achieve an increased clamping force and resultant increased clamping pressure between the clamps' opposing jaws. This failure is attributed to the fact that presently-available clamps utilize lever mechanisms having a through opening, defining an interior contact surface to grip opposing sides of the clamp's bar, in creating the requisite jaw pressure. Because one-handed bar clamps typically utilize rectangular-shaped bars to connect the opposing jaws together, it is functionally advantageous that the lever-mechanisms of these clamps grip the sides of the rectangle having the smaller corner-to-corner dimensions. Gripping the sides of the rectangle having the smaller corner-to-corner dimensions allows the lever to grip the bar at a reduced angle, which makes the mechanism easier to operate. However, gripping the smaller corner-to-corner dimensions of a given rectangle results in a reduced frictional area, thereby resulting in reduced clamping strength.
Another such disadvantage is a failure of the presently available quick-grip clamps to maintain initially-created clamping forces over time. Presently-available quick grip clamps utilize a driving lever mechanism to drive the jaws of the clamp together and a locking lever mechanism to hold the jaws in place, once the driving mechanism is released. The disadvantage with the locking lever mechanism is that, for the locking lever to move in relation to the connecting bar, it must have a different angular relationship with the connecting bar during a release function than when it is performing its locking function. This angle change allows for the clamp ends to move away from one another, thus resulting in a loss in clamping pressure generated by the driving lever mechanism.
Another disadvantage is that the locking lever locks onto the connector bar at the 90° corners of its interior contact surface. The locking lever interior contact surface may also contact the bar at either a single point on the top of the bar or at two points on the radii of the bar. The contact geometry of these respective contact surfaces can wear easily and result in slip, thus affecting the clamp's holding strength.
Thus, it would be advantageous if the mechanism of a quick-grip clamp could grip the sides of the rectangular-shaped bar having the longer corner-to-corner dimensions to create increased jaw pressures between the clamps' opposing jaws. It would also be advantageous if the mechanism altogether eliminated the locking lever and resultant slip, thus allowing the clamp to maintain initially-created clamping forces over time. The present invention thus provides these and other advantages.